Consciousness and Cognition最新文献

Decision confidence plays a critical role in humans' ability to make adaptive decisions in a noisy perceptual world. Despite its importance, there is currently little consensus about the computations underlying confidence judgements in perceptual decisions. To better understand these mechanisms, we addressed the extent to which confidence is informed by a naturalistic prior distribution. Contrary to previous research, we did not require participants to internalise parameters of an arbitrary prior distribution. We instead used a novel psychophysical paradigm leveraging probability distributions of low-level image features in natural scenes, which are well-known to influence perception. Participants reported the subjective upright of naturalistic image patches, targets, and then reported their confidence in their orientation responses. We used computational modelling to relate the statistics of the low-level features in the targets to the average distribution of these features across many naturalistic images, a prior. Our results showed that participants' perceptual and importantly, their confidence judgments aligned with an internalised prior for image statistics. Overall, our study highlights the importance of naturalistic task designs that capitalise on existing, long-term priors to further understand the computational basis of confidence.

Psychedelic drugs offer valuable insights into consciousness, but disentangling their causal effects on perceptual and high-level cognition is nontrivial. Technological advances in virtual reality (VR) and machine learning have enabled the immersive simulation of visual hallucinations. However, comprehensive experimental data on how these simulated hallucinations affects high-level human cognition is lacking. Here, we exposed human participants to VR panoramic videos and their psychedelic counterparts generated by the DeepDream algorithm. Participants exhibited reduced task-switching costs after simulated psychedelic exposure compared to naturalistic exposure, consistent with increased cognitive flexibility. No significant differences were observed between naturalistic and simulated psychedelic exposure in linguistic automatic association tasks at word and sentence levels. Crucially, visually grounded high-level cognitive processes were modulated by exposure to simulated hallucinations. Our results provide insights into the interdependence of bottom-up and top-down cognitive processes and altered states of consciousness without pharmacological intervention, potentially informing both basic neuroscience and clinical applications.

Asking participants to Think Aloud is a common method for studying conscious experience, but it remains unclear whether this approach alters thought qualities-such as meta-awareness, rate of topic shifts, or the content of thoughts in task-absent conditions. To investigate this, we conducted two studies comparing thinking aloud to thinking silently. In Study 1, 111 participants alternated between 15-minute intervals of verbalizing and silently reflecting on their stream of consciousness in a counterbalanced design. A subset also reported topic shifts intermittently via self- and probe-catching methods. Results showed that the stream of consciousness was minimally reactive to the Think Aloud protocol, with no significant differences in meta-awareness and topic shifting rates. Moreover, among 21 thought qualities and 18 content topics analyzed, only three qualities (private thoughts, mind blanking, and session difficulty) and one topic (partner, intimacy, love, and sexual matters) differed between Think Aloud and Silent Think. In Study 2, 102 participants either did Think Aloud or Silent Think while responding to thought probes. Findings replicated the lack of differences in the frequency and meta-awareness of topic shifts between Think Aloud and Silent Think. Furthermore, no differences in reported cognitive load were observed between the two conditions. These results emphasize the value of the Think Aloud procedure for examining the stream of consciousness, demonstrating its reliability and minimal impact on the natural flow of thoughts. Thus, Think Aloud offers a robust model system for examining the otherwise unverbalized stream of consciousness in task-absent contexts.

The encoding of episodic memories depends on segmentation; memory performance improves when segmentation is available and performance is impaired when segmentation is absent. Indeed, for episodic memories to be created, the encoding of information into long-term memory requires the experience of event boundaries (i.e., context-shifts defined by salient moments of change between packets of to-be-learned stimuli). According to this view episodic encoding, and therefore learning, is critically dependent on the nature of working memory. Motived by this theoretical framework, here we explore the effects of segmentation on long-term memory performance, investigating the possibility of optimising learning by aligning the presentation of stimuli to the capacity of working memory. Across two experiments, we examined whether manipulating the boundaries between events influences memory. Participants travelled within a virtual environment, with spatial-temporal gaps between virtual locations providing context-shifts to segment sequentially presented lists of words. Both accurate recall and memory for temporal order improve and the number of falsely recalled words reduces when reducing the quantity of information presented between boundaries. Taken together, the present results suggest that closely matching the quantity of information between boundaries to working memory capacity optimises long-term memory performance.

Items held in visual working memory (VWM) influence early visual processing by enhancing memory-matching visual input. Depending on current task demands, memory items can have different priority states. Here, we investigated how the priority state of items in VWM affects two key aspects of early visual processing: access to visual awareness and attention allocation. We used three perceptual tasks: the breaking continuous flash suppression task (Experiment 1), the attentional capture task (Experiment 2), and a visual search task (Experiment 3). We found that stimuli matching prioritized VWM items yielded a large perceptual advantage over stimuli matching non-prioritized VWM items (despite minimal memory loss). Additionally, stimuli matching non-prioritized memory items exhibited a (small but consistent) perceptual advantage over VWM-unrelated stimuli. Taken together, observers can flexibly de-prioritize and re-prioritize VWM contents based on current task demands, allowing observers to exert control over the extent to which VWM contents influence concurrent visual processing.

For millennia, humans have created drawings as a means of externalizing visual representations, and later, to aid communication and learning. Despite its cultural value, we understand little about the cognitive states elicited by drawing, and their downstream benefits. In two preregistered experiments, we explored these states; Undergraduate participants (Ns = 69, 60) encoded words by drawing or writing, periodically describing their thoughts using multi-dimensional experience sampling, a tool for characterizing the features of ongoing thought. Subsequent memory was tested via free recall. Contrasted with writing, drawing improved memory, and evoked thoughts that were more visual and elaborative. Recall was also dictated by the emergence of these thought patterns, with the former most important when drawing. Our findings establish that drawing elicits unique thought patterns that promote successful memory, providing an explanation for drawing's influential role in our everyday lives.

Free-choice behavior is unique in that actions are internally self-determined, unlike forced-choice behavior, which is externally specified. Several studies suggest these two action modes can lead to different behavioral, affective, and motivational outcomes. We examined whether people estimate free-choice differently from forced-choice processing time due to possible introspective biases associated with these modes. Consistent with previous studies, free choices were slower than forced choices and action mode interacted with perceptual difficulty. Importantly, all effects in mean reaction times (RTs) were mirrored in mean introspective RTs (iRTs). Moreover, objective RTs alone could essentially predict iRTs without any contributing distortion of choice modes. Thus, introspection about RT appears equally accurate for both externally and self-determined actions, suggesting that iRTs are primarily based on a direct read-out of temporal information. Possibly, accurate introspection about processing time is a crucial basis for potentially distinct subjective experiences of free and forced choices.

The aim of the current study was to investigate visual scan patterns for the self-face in infants with the ability to recognize themselves with a photograph. 24-month-old infants (N = 32) were presented with faces including the self-face in the upright or inverted orientation. We also measured infants' ability to recognize oneself in a mirror and with a photograph. Results showed that only in trials with the self-face was pupil dilation greater in the upright orientation than in the inverted orientation, and that eye movements and pupil dilation were not associated with PSR tasks. Our findings suggest that the processing of the self-face was processed in a manner similar to that of others, with longer and more fixations on eyes and nose, but infants allocated more attentional resources to processing upright self-face. Self-face processing in infancy may be independent of the understanding of the self beyond the here and now.

Contrary to the leading theories of consciousness on offer, it is a fruitful working hypothesis that conscious experiences facilitate a variety of functional capacities that are distinct to particular psychological tasks, individuals, and species (i.e., functional pluralism). In this paper, I illustrate this novel methodological point by identifying some of the functional contributions that consciousness makes to (human) emotional processing. I first consolidate empirical evidence of the capacities and limitations of unconscious emotional processing, drawing on a) experimental paradigms that employ the tools of vision science (masking and suppression of emotionally relevant stimuli), and b) theoretical and clinical research on emotional disorder (Generalized Anxiety Disorder). After comparing the functional characteristics of unconscious and conscious emotional processes, I argue that conscious experiences facilitate a cluster of functions that are specific to emotion, including increased capacities for representing fine-grained evaluative information, inhibition, and flexible response.

Motor imagery (MI) is a cognitive process believed to rely on the representation developed through experience. The equivalence between MI and execution has been questioned and the relationship between experience types and MI is unclear. We tested how observational and physical practice of hand gesture sequences impacted visual and kinesthetic MI and transfer to the unpracticed effector. Three groups (n = 22/gp.); no-vision physical practice, observational practice and no-practice control, practiced and visually and kinesthetically imagined performing the sequences. MI was assessed using mental chronometry, a movement time (MT) congruency measure and subjective ratings. Physical practice improved kinesthetic MI ratings and observational practice improved visual MI ratings. Contrary to predictions, physical practice did not enhance timing congruency. Imagined MTs were longer in transfer after physical practice, suggesting MI was not based on the same representation. These data question ideas of equivalence, with poor temporal matching after no-vision physical practice.